ABSTRACT Adolescence is a period of marked cognitive development, reflected by improvements in the ability the effectively and consistently engage brain networks associated with cognitive control. However, while a wealth of behavioral and functional imaging studies have provided detailed insight into mean patterns of adolescent development, methodological challenges have limited our understanding of individual age-dependent trajectories. This has impeded the characterization of a template of ?typical? development, undermining our ability to link atypical development to the emergence of psychopathology. This difficulty arises due to cross-sectional and longitudinal studies with few follow-up assessments that track subjects over only a small window of their development, and is exacerbated by evolving technologies and research protocols that limit the ability to track true developmental change. Finally, the specificity of cognitive tasks used has led to disparate results, limiting our ability to understand development of cognitive control as a construct. We propose a novel analysis of an existing 10-year longitudinal data set that includes yearly task fMRI collected on a scanner with no hardware and minimal software upgrades, and behavioral assessments using a broad battery of cognitive tasks. The parent grant has produced a growing literature charting changes in task-related cognitive brain function and behavior, and related changes in white matter integrity. However, this study began prior to the establishment of resting state fMRI for characterizing functional brain networks, and thus this was not an aim, nor were continuous periods of rest included. Nevertheless, the study used a block design paradigm that allows for the assessment of resting state connectivity within ?off? periods, as previously described in the literature, which we demonstrate offers a viable means for assessing functional brain networks in developmental populations. In addition, an extensive cognitive assessment was gathered, and specific aspects of cognitive control (e.g., working memory, inhibitory control) have been extensively analyzed. However, recent approaches allow core mechanisms shared across cognitive tasks to be estimated as a ?domain-general cognitive control? component that can better characterize development of the overarching processes of cognitive control. We propose to mine this longitudinal data in an innovative manner not envisioned in the parent grant to characterize individual developmental trajectories of functional connectivity and their associations to a domain general component of cognitive control. We will identify connectivity patterns showing developmental change through adolescence associated with increases in domain-general measures of cognitive control. Finally, we will characterize individual age- dependent trajectories for both connectivity and behavior to identify variation in patterns of maturation, their early-adolescent predictors, and their relationship to adult outcomes. These results will inform the range of changes in adolescent brain architecture and how these are related to cognitive control normatively, which is critical for setting a template from which to understand aberrant maturation such as in psychopathology.